Performance Evaluation of a High Resolution Non-Human Primate PET/CT System

• Published in: The Journal of nuclear medicine (1978)
• Main Authors: Sarnyai, Zsolt, Nagy, Kálmán, Patay, Gergely, Molnár, Milán, Rosenqvist, Göran, Tóth, Miklós, Takano, Akihiro, Gulyás, Balázs, Major, Péter, Halldin, Christer, Varrone, Andrea
• Format: Journal Article
• Language: English
• Published: United States 13.07.2019
• Subjects: preclinical PET; multimodality imaging; Animal Imaging; PET/CT imaging; PET/CT; performance evaluation; NHP imaging; PET
• ISSN: 1535-5667

The Large Field of View Extreme Resolution Research Imager (LFER) 150 PET/CT by Mediso is a high-resolution system for non-human primate (NHP) imaging. The objective of this study was to evaluate the performance of the system using the National Electrical Manufacturers Association (NEMA) NU 4-2008 standard protocol. As a preliminary in vivo evaluation of the system a PET measurement in a NHP was also performed. Resolution, sensitivity, image quality and noise equivalent count rate (NEC) were measured. NEC measurement was performed with a rat-like and a monkey-like phantom. A Derenzo phantom experiment was carried out to test the resolution using three-dimensional ordered subset expectation maximization reconstruction. One cynomolgus monkey (4.5 kg, IV ketamine/xylazine anesthesia) was examined with the dopamine transporter radioligand F-FE-PE2I (94 MBq) to evaluate the in vivo performance of the system. List mode PET data acquired for 93 min were reconstructed into 38 frames with the Tera-Tomo™ 3D engine. Binding potential values (BP ) for caudate nucleus, putamen and substantia nigra were evaluated using the simplified reference tissue model. Radial full width half maximum resolution using Fourier rebinning and 2D filtered back projection algorithm was <2.2 mm and <3.2 mm in the central 60 mm and 140 mm diameter region, respectively. Maximum sensitivity in 400-600 keV and 250-750 keV energy window was 30.03 cps/kBq (3.3%) and 49.11 cps/kBq (5.4%), respectively. The uniformity in the image quality phantom was 3.3 % and the spill-over ratio for air and water was 0.1. The peak of the NEC curve was 430 kcps (at 115 MBq) with the rat-like phantom and 78 kcps (at 139 MBq) with the monkey-like phantom. Rods of the Derenzo phantom with 1 mm diameter could be distinguished by eye. In the NHP experiment, BP values in the caudate, putamen and substantia nigra (4.9, 4.9 and 1 respectively) were similar to those previously reported using the same radioligand and a high resolution research tomograph. The results obtained from phantom experiments and one representative PET measurement in NHP confirm that the LFER 150 is a high-resolution PET-CT system with suitable performance for brain imaging in NHPs.